Spiral model: The spiral model is an

The spiral model is an SDLC model that combines elements of an iterative software development model with a waterfall model . It is advisable to use this model for expensive, large and complex projects. The spiral model is a systems development lifecycle (SDLC) method used for risk management that combines the iterative development process model with elements of the Waterfall model . The spiral model is used by software engineers and is favored for large, expensive and complicated projects. The spiral model is a risk-driven software development process model that blends elements of other approaches based on the project's risk patterns. Learn about its history, characteristics, invariants, milestones, and applications from this Wikipedia article. What is Spiral Model ? The spiral model is a software process model that couples the iterative nature of prototyping with the controlled and systematic aspects of the linear sequential model . Barry Boehm mentioned the Spiral model in this paper (1986). The spiral model is also known as meta- model since it encompasses all other life cycle models.